Rotating electrical machine such as an alternator adaptable to different types of motor vehicles engines

ABSTRACT

The invention concerns a rotary electrical machine such as an alternator, in particular for a motor vehicle.  
     This machine is adaptable to various types of motor vehicle engine and comprises removable lugs ( 16 ) for fixing the machine to a fixed support such as a support secured to the vehicle engine and which are able to be mounted on the peripheral face of at least the front bearing ( 2 ), each between two lateral support faces ( 14 ) provided on this peripheral surface at a predetermined distance from each other in the peripheral direction of the bearing. The machine is characterised in that an aforementioned lateral support face ( 14 ) is formed by the lateral face of an area of protruding material ( 12 ), which constitutes an alternator assembly area, and in that an aforementioned fixing lug ( 16 ) is disposed between two lateral support faces ( 14 ) opposite each other and belonging to two adjacent protruding areas ( 12 ).  
     The invention can be used by motor vehicle alternators.

TECHNICAL FIELD OF THE INVENTION

[0001] The invention concerns a rotary electrical machine such as analternator, in particular for a motor vehicle, adaptable to variousmotor vehicle engines, of the type comprising a casing enclosing astator and a rotor whose spindle is supported by front and rear bearingsand carries a pulley driven by means of a belt and removable fixing lugsable to cooperate with a support fixed to the vehicle engine, and whichare able to be mounted on the peripheral face of at least the frontbearing, each between two support faces provided on this peripheral faceat a predetermined distance from each other in the peripheral directionof the bearing.

PRIOR ART

[0002] Alternators of this type are already known. Their main field ofapplication is the-automobile market relating to spare parts, that is tosay replacement parts, and small production runs. This is because, byvirtue of their removable fixing lugs, alternators are adaptable tovarious types of motor vehicle engine.

[0003] French patent application N^(o) 2 793 300 describes an alternatoras indicated above, in which there is machined, in a protruding area onthe peripheral surfaces of the front and rear bearings, a dovetailgroove which extends parallel to the axis of the two bearings and whichis intended to receive two fixing lugs.

[0004] These lugs are able to be moved by sliding in this groove and canbe immobilised therein at an axial distance from each other by clampingscrews passing through holes formed in the lateral walls of the dovetailgrooves. The front bearing is also configured so as to allow themounting in various angular positions of a lug for tensioning the drivebelt. For this purpose, the front bearing comprises a peripheral rib inthe form of an arc of a circle and, in front of the lateral face of thisrib, which is oriented towards the pulley and extends radially, an axialsupport face for the tensioning lug. This lug can be moved angularly onthis support face and can be immobilised in various angular positions byscrews passing through the lug and engaging in threaded holes in theradial rib face.

[0005] Because of their single dovetail groove in the bearings, thealternator known through this French patent has the major drawback ofnot being able to allow a choice of the relative position of the rearconnections, which is becoming more and more critical because of theconstraints of location and size of the alternators in theirenvironment. According to the vehicle, the position of the B⁺ outputterminal of the alternator may have a different angular position.

[0006] The peripheral rib in the form of an arc of a circle of theaforementioned known alternator constitutes a known obstacle toproducing several protruding areas regularly distributed angularly onthe external periphery of the front and rear bearings of the alternator.

[0007] The aforementioned alternator also has the drawback of notallowing permutation of the fixing lugs with the belt tensioning lug.This is because the fixing lugs inserted in the groove in the protrusionare designed to bear the major part of the weight of the alternatorwhilst the belt tensioning lug is carried by the peripheral rib in theform of an arc of a circle, not designed to bear the weight of themachine by means of fixing lugs. Thus the alternator described in theaforementioned patent application can find an application only foralternators necessarily comprising at least one belt tensioning lug.This alternator can therefore not be used for motor vehicles in whichthe alternator does not have a belt tensioning lug but only three orfour fixing lugs. In this case, a device external to the alternatoreffects the tensioning of the belt.

OBJECT OF THE INVENTION

[0008] The aim of the present invention is to propose an alternator ofthe type indicated above which mitigates the drawbacks of the knownalternators which have just been stated and is adapted to the manyapplications in the field of motor vehicles, required by the marketconsisting of replacement parts and short production runs.

[0009] For this purpose it proposes a rotary electrical machine such asan alternator, in particular for motor vehicles, adaptable to varioustypes of motor vehicle engines and comprising a casing enclosing astator and a rotor whose spindle is supported in front and rear bearingsand carries a pulley for driving by means of a belt, and removable lugsfor fixing the machine to a fixed support such as a support secured tothe vehicle engine and which are able to be mounted on the peripheralface of at least the front bearing, each between two lateral supportfaces provided on this peripheral surface at a predetermined distancefrom each other in the peripheral direction of the bearing, in which anaforementioned lateral support face is formed by the lateral face of anarea of protruding material on the external peripheral surface of thebearing, and in that an aforementioned fixing lug is disposed betweentwo lateral support faces opposite each other and belonging to twoadjacent protruding areas.

[0010] Thus the invention proposed makes it possible to choose therelative position of the rear connections of the alternator in order tofacilitate its connection in the motor vehicle. The invention also hasthe advantage of offering the possibility of choosing the location whereit is wished to put the fixing lugs on the external peripheral surfaceof the bearing. Another advantage according to the invention consists ofoffering the possibility of using only fixing lugs or again using fixinglugs in combination with at least one belt tensioning lug.

[0011] The invention is advantageously supplemented by the variousfollowing characteristics, taken alone or in all their technicallypossible combinations:

[0012] the two lateral support faces and the peripheral surface portionof the machine, between the two lateral faces, constitute a runner forreceiving and positioning a fixing lug,

[0013] a protruding area is formed by an area serving for assembling themachine,

[0014] an aforementioned bearing carries on its external peripheralsurface a multitude of protruding areas delimiting a plurality ofrunners advantageously distributed equidistantly,

[0015] a fixing lug comprises a base part by means of which the lugengages in the positioning runner and a top part for fixing to theaforementioned fixed support,

[0016] a fixing lug is produced in the form of a single piece whose baseand top parts are constituent parts,

[0017] the base and top parts are separate pieces, able to be assembledfor forming a fixing lug,

[0018] a fixing lug is fixed in its positioning runner by a clamp devicebearing through one part on the base of the fixing lug and throughanother part on the adjacent protruding area,

[0019] the base of the fixing lug has a width less than the width of therunner intended for receiving it and in that the fixing clamp devicecomprises an element in the form of a wedge which engages in the gapcreated when the base is pushed in abutment against the other supportface and provides by a wedging effect the immobilisation of the base inits runner when the fixing screws are tightened,

[0020] the clamp device has the general shape of an L, one arm of whichforms the aforementioned wedge element whilst the other arm comes intoabutment on the protruding area of the periphery of the bearing,

[0021] the clamp device comprises a piece forming a separate wedge and aclamping plate coming into abutment on the protruding area and the pieceforming a wedge,

[0022] the clamp device comprises a piece forming a wedge of trapezoidalshape and a clamping plate coming into abutment on the base of the lugand the protruding area and in that the wedging effect is produced by aclamping screw passing through the plate and the wedge piece and duringtightening drawing the wedge piece towards the plate,

[0023] the clamp device comprises a clamping plate, part of which comesinto abutment on the protruding area whilst another part comes intoabutment on an inclined surface forming a ramp configured so as toproduce a force pushing the base of the clamp against the oppositerunner support face when the plate part is clamped against theprotruding area,

[0024] a lug base has, in the plane of its receiving runner, the generalshape of a U so as to leave free, in its central part, the ventilationholes formed in the peripheral wall of the bearing,

[0025] a lug base comprises an aperture for leaving free the ventilationholes formed in the peripheral wall of the bearing,

[0026] the surface portions of the clamp device and of the fixing lugbase which are in abutment on each other are notched, the notchesadvantageously extending perpendicularly to the axis of the machine inorder to improve the axial immobilisation of the fixing lugs,

[0027] the face for placing the base of a fixing lug on the peripheralsurface of the bearing has a curvature corresponding to that of thesurface portion of the bearing surface between the two lateral supportfaces.

SUMMARY DESCRIPTION OF THE DRAWINGS

[0028] Other characteristics and advantages of the invention will emergeclearly from the description which is given below, by way of indicationand in no way limiting, with reference to the accompanying drawings, inwhich:

[0029]FIG. 1 is a perspective view of the casing of an alternatoraccording to the invention;

[0030]FIG. 2 is a view in the direction of the arrow II in FIG. 1;

[0031] FIGS. 3 to 6 are schematic views, similar to FIG. 2, of fourversions of an embodiment of the mounting of a removable fixing lugaccording to the invention;

[0032]FIG. 7 is a detail view, to a larger scale, of the area encircledat VII in FIG. 5;

[0033]FIG. 8 is a detail view, to a larger scale, of the area encircledat VIII in FIG. 6;

[0034]FIG. 9 is a perspective view of a variant embodiment of a fixinglug according to the invention;

[0035]FIG. 10 is a view to a larger scale of the part indicated at X inFIG. 1.

DESCRIPTION OF PREFERENTIAL EMBODIMENTS OF THE INVENTION

[0036]FIG. 1 shows a casing designated by the general reference 1 of analternator for a motor vehicle. This casing encloses, in a manner knownper se, a stator and a rotor and associated devices. The alternatorstructure, inside the casing, will not be described in more detail sincethe invention does not relate to it.

[0037] The casing 1 is formed by the assembly of front 2 and rear 3bearings intended, in a manner known per se, to support the spindle ofthe alternator rotor.

[0038] As shown in particular in FIG. 1, each bearing has a conventionalconfiguration, that is to say it has the form of a cup comprising acylindrical peripheral wall 5 and a bottom wall 6 at the centre of whichis situated the passage orifice 7 for the rotor shaft, surrounded by aring of passage orifices 8 for the flow of a cooling fluid. In theperipheral part 5 and the adjacent part of the bottom 1 there are formedfour series of lateral holes 9 for discharge of the cooling fluid.

[0039] The bearings also carry, on their cylindrical peripheral face 5,distributed angularly in an equidistant fashion, four areas ofprotruding materials 12, which advantageously constitute the assemblyareas for the alternator through which there pass the tie rods intendedto fix the front and rear bearings. An assembly area can also, wherenecessary, be intended for fixing the stator. These protruding areas 12extend parallel to the axis of each bearing and the areas 12 of onebearing are aligned with the areas 12 of the other. Thus, by using thepre-existing assembly areas, the radial ventilation holes are notobstructed, which guarantees optimum cooling of the alternator.

[0040] According to an essential aspect of the invention, theseprotruding areas 12 are used to make the casing 1 and thus thealternator adaptable to various types of motor vehicle engine. As shownin particular by FIGS. 3 to 6, for this purpose the lateral faces 14 ofthe protruding areas 12 are configured so as to be able to position,between the opposite faces 14 of two adjacent protruding areas 12, a lug16 for fixing the casing to a support of the motor vehicle engine ordirectly to this engine. It should be noted that the lugs 12 can be usedeither as fixing lugs or as lugs for tensioning the belt driving theconventional pulley, known per se and therefore not depicted.

[0041] As can be seen in the figures, a lug 16 according to theinvention which is thus removable is composed of a base part 17 and atop part 18. The base part 17 provides the interface with the bearingand is intended to engage in the corresponding two lateral faces 14 ofthe two protruding areas 12 adjacent to the periphery of the bearing.The face 20 for placing the base 17 of the lug on the peripheral surface5 of the bearing has a curvature corresponding to that of the surfaceportion 21 of the surface 5 between the two lateral support faces 14.The base enables the lug to slide in the runner formed in the portion ofthe peripheral face 21 of the bearing and of the two lateral faces 14 ofthe two protrusions 12. The base 17 comprises, for its final fixing,notched lines, depicted at 24 in FIG. 10, perpendicular to the axis ofthe alternator, on the top of the base cooperating with fixing members12 which are described below. The length, in the axial direction, of thesliding base 17 of the lug depends on the axial offset of the lug, ascan be seen in FIG. 1, but must allow secure final fixing of the lug onthe bearing and at the same time leave clear the outlet holes 9. Asshown in FIG. 1, the lug base 17 can have, in the plane parallel to therunners, a U-shaped profile, the external edges of the arms cooperatingwith the support faces 14. By virtue of this profile, the holes 9 canremain clear.

[0042]FIG. 9 illustrates a variant embodiment of a fixing lug 16according to the invention. In this case, the lug base 17 is providedwith an aperture 42 which leaves the holes 9 clear.

[0043] The top part 18 of a lug 16 provides the interface with theengine of the motor vehicle. It is provided with a hole 19 for fixing itto the support of this engine, circular in shape for the fixing lugs asdepicted in FIGS. 1, 2, 9 or 10, or oblong for the belt tensioning lugsas depicted in FIGS. 3 to 6. Naturally the shape of the holes 9 for thefixing or belt tensioning lugs can have shapes different from thosedescribed above. Thus, for example, the belt tensioning lugs can alsohave threaded or smooth circular holes 19. The lug may be different fromone application to another according to the angular position, the heightof the axis, the diameter of the bore and the thickness of its hub,which makes it necessary to have available a certain number of differentlugs for covering the various cases of application. It should be notedthat the lugs of the front and rear bearings are interchangeable andthat the base and top parts may belong to the same piece or be twopreassembled pieces.

[0044] The adjustment of the position of a fixing lug 16 or a belttensioning lug in its runner and its final fixing in the appropriateposition on the support bearing is effected by means of a clamp 22 whichis placed so as to laterally cover the lug 15 to be fixed on the part ofthe bearing external to the cover, that is to say the external surfaceof the protruding area 12 in the vicinity of the runner. The clamp isfixed to the bearing by means of at least one screw 23 located inthreads formed in the protruding area 12. Advantageously there may be anotched area. The internal surface of the part of the flange which comesinto abutment on the notched area 24 on the top of the lug base 17 isnotched as indicated at 26 in FIG. 10, so as to correspond to thenotches on the base. The coinciding of the notched parts of the lug andflange is facilitated by a clearance or an oblong shape of the holes inthe clamp, making it possible when a screw is tightened to slightly movethe clamp. Thus the lug will also be positioned exactly at the requiredplace. In this way the axial immobilisation of the fixing lugs isensured.

[0045] FIGS. 3 to 6 show four possibilities of a fixing of a lug 16 in arunner of a front or rear bearing.

[0046] In the solution depicted in FIG. 3, the two lateral faces 14 ofthe runner form an angle a with the bottom 21 of the runner, which isless than or equal to 90°.

[0047] The two lateral faces 25 of the base 17 of the lug 16 have aninclination corresponding to that of the faces 14, but the width of therunner of the bearing is greater than the width of the base 17. Thus,when the lug is placed in its runner, one lateral face 25 is pressed ona support face 14 of the bearing. However, on the other hand, thereexists a clearance 27 for example of several millimetres between theother lateral face 25 of the base and the corresponding support face 14of the runner.

[0048] In order to fix the base 17 of the lug 16 in the bearing runner,a clamp 22 is used which has on one side a projecting portion in theform of a wedge 28 which engages in the gap 27 between the two separatedfaces 25 and 14 and, by a wedging effect, ensures the locking of thebase 17 of the lug 16 in the runner when the screws 23 are clamped.According to its length, the clamp can comprise an appropriate number offixing screws. Advantageously, the orientation of the screws is notradial and the axis of the screws forms with the peripheral surface ofthe tangent to the surface of the protrusion 12 on the side opposite tothat of the face 14 an angle of less than 90°.

[0049] Advantageously, according to another embodiment of the invention,the two faces 14 of two adjacent protrusions 12 form a runner for afixing lug 16 having different angles. On the one hand, the angle α,previously described, formed by the lateral face 14 of the runner withthe bottom 21 of the runner is less than 90° for the side of the runneropposite to that carrying the flange 22 and, on the other hand, theangle a formed by the side of the runner carrying the flange 22 is equalto or less than 90°. The face 14 cooperating with the fixing flange 22has a roughly radial, or even radial, direction, which has the advantageof radially guiding the flange 22 well when the screws 23 are screwedand thus improving the locking of the fixing lug 16 by better abutmentof the clamp 22 on the face 25 of the facing lug 16.

[0050] Advantageously, whatever the embodiment, the two lateral faces 25of the base 17 of the lug 16 have an inclination corresponding to thatof the face 14 opposite to that carrying the clamp. Thus it is possibleto insert the fixing lugs in the groove indifferently in one of the twopossible directions in the axial direction of the groove.

[0051] Advantageously, the material used for producing the clamp is asintered steel which has the characteristic of being of low elasticityand economical.

[0052] The fixing solution depicted in FIG. 4 corresponds in itsprinciple to the solution depicted in FIG. 3. The only appreciabledifference lies in the fact that the part of the wedge 28 is now formedby a separate piece 30 which will be pushed into the gap 27 by a clampplate 31, when the screws 23 are tightened.

[0053] Fixing by means of a wedge has the advantage that there is addedto the fixing by pressure a lateral component due to the wedging forcesexerted. Advantageously, the material used for the form of the wedgeclamp incorporated could be based on steel, and hence there will resulta smaller space requirement than with a choice of material made fromaluminium alloy.

[0054]FIG. 5 illustrates a method of fixing by means of a clamp 22 inthe form of a plate 35 which cooperates with a member in the form of awedge with a trapezoidal cross-section 32, as can be seen in more detailin FIG. 7. In this embodiment, the lateral support surface 25 of the lugbase 17 on the same side as the application of the clamp plate 35 has aninclination which is opposite to that of the support face 14 of therunner. When it is wished to position the lug 16 in its runner, thelateral face 25 of the lug base 17 and the corresponding support face 14of the runner are put in abutment on one side and the trapezoidal-shapedpiece 32 is inserted in the gap between the other pair of faces 25 and14. The piece 32 comprises two threaded holes each intended to receive aclamping screw denoted 36 which passes through the clamp 22 andtherefore the head 36 bears on the top face of the clamp. When thescrews 36 are tightened, the trapezoidal piece 32 which is captive tendsto rise up and wedge between the faces 25 and 14. The result is animmobilisation and securing of the lug in its runner.

[0055]FIG. 6 illustrates one advantageous fixing mode. According to thismode, one face of the runner indicated by the specific reference 14′,instead of being inclined like the support faces 14, forms a right anglewith the bottom of the runner at this point, that is to say extendssubstantially radially, as shown by the figure. The correspondinglateral face 25′ of the lug base 17 has the same orientation as the face14′. The edge of the lug base 17 along the base 25′ has an inclinationand constitutes a lateral thrust ramp 38. The clamp device 22 inaddition to the ramp 38 has a plate 39 angled in an appropriate fashion,which rests through an arm 40 on the external area of the runner andthrough its inclined arm 41 on the ramp 38. When the arm 39 in abutmenton the bearing is clamped by the clamping screws 23 against the surfaceof the bearing, the arm 40 in abutment on the ramp 38 pushes the base 17of the lug 16 in its runner on the opposite support face 14.

[0056] The fixing mode according to FIG. 6 has the advantage that thelug thus fixed will be wedged in its runner housing. The material of theclamp could be different from that of the bearing, if that provednecessary for its resistance to the forces. The opposite faces of theflange and lug could have serrations which would afford a betterresistance to axial sliding.

[0057] It is clear from the above description that, by virtue of thesystems for fixing the removable lugs which have just been described,the invention makes it possible to use alternators from conventionalmass production for various types of motor vehicle. The invention makesit possible to adapt such an alternator to a given type of motor vehicleengine simply by locating fixing lugs in one or more runners angularlydistributed around the front and/or rear bearings, by pivoting, perquarter in the case described of four runners, of the position of theelectrical terminals and by appropriate axial positioning of the lugs intheir runner. By virtue of the notching of the cooperating services, afixing on lugs in their runner is obtained.

[0058] Naturally various modifications can be made to the invention asdescribed above and depicted in the figures. Thus the number ofprotrusion areas on the periphery of the bearings and thus the number ofrunners could be different from four. It could also be envisaged fixingthe lugs directly to the bearing by providing oblong holes in the partsor shrinking them on after positioning in their positions.

[0059] The invention particularly finds an advantage in the industry ofthe reconditioning of alternators of all origins allowing standardexchange consisting of making a worn appliance operational once againafter having restored it, for example by cleaning, machining orreplacing defective components. Thus a renovated electrical machineaccording to the invention allows the reconstruction of electricalmachines which may be dedicated to applications other than the originalones. This electrical machine according to the invention makes itpossible to reduce stocks at motor vehicle repairers since one and thesame machine can be dedicated to several types of motor vehicle ratherthan limited to a single original application.

[0060] These alternators produced according to the invention thereforeconstitute “multi-application alternators”.

[0061] Multi-application alternators can be equipped with magneticcircuits and regulation and rectifying systems making it possible tosupply the voltage currently in use on 14-volt cars but also all othervoltages such as 6, 28 or 42 volts. Likewise these alternators couldsupply direct or alternating current and fulfil all the additionalfunctions associated with the voltage regulator.

[0062] Multi-application alternators, new or reconditioned, can becooled by air or by a cooling liquid. Alternators cooled by airaccording to the invention are provided with internal or externalventilation. Alternators cooled by a cooling liquid comprise, in amanner known per se, double walls allowing the circulation of thecooling liquid. In this case, the holes for fixing the clamps will beblind rather than opening out.

1. Rotary electrical machine such as an alternator, adaptable to varioustypes of motor vehicle engines and comprising a casing enclosing astator and a rotor whose spindle is supported in front and rear bearingsand carries a pulley for driving by means of a belt, and removable lugsfor fixing the machine to a fixed support such as a support secured tothe vehicle engine and which are able to be mounted on the peripheralface of at least the front bearing, each between two lateral supportfaces provided on this peripheral surface at a predetermined distancefrom each other in the peripheral direction of the bearing,characterised in that an aforementioned lateral support face (14, 14′)is formed by the lateral face of an area of protruding material (12) onthe external peripheral surface of the bearing, and in that anaforementioned fixing lug (16) is disposed between two lateral supportfaces (14, 14′) opposite each other and belonging to two adjacentprotruding areas (12).
 2. Rotary electrical machine according to claim1, characterised in that the two lateral support faces (14, 14′) and theperipheral surface portion (21) of the machine, between the two lateralfaces, constitute a runner for receiving and positioning a fixing lug(16).
 3. Rotary electrical machine according to claim 1, characterisedin that a protruding area (12) is formed by an area serving forassembling the machine.
 4. Rotary electrical machine according to claim2, characterised in that an aforementioned bearing (2, 3) carries on itsexternal peripheral surface a multitude of protruding areas (12)delimiting a plurality of runners advantageously distributedequidistantly.
 5. Rotary electrical machine according to claim 1,characterised in that a fixing lug (16) comprises a base part (17) bymeans of which the lug engages in the positioning runner and a top part(18) for fixing to the aforementioned fixed support.
 6. Rotaryelectrical machine according to claim 5, characterised in that a fixinglug (16) is produced in the form of a single piece whose base (17) andtop (18) parts are constituent parts.
 7. Rotary electrical machineaccording to claim 5, characterised in that the base (17) and top (18)parts are separate pieces, able to be assembled for forming a fixing lug(16).
 8. Rotary electrical machine according to claim 2, characterisedin that a fixing lug (16) is fixed in its positioning runner by a clampdevice (22) bearing through one part on the base (17) of the fixing lug(16) and through another part on the adjacent protruding area (12). 9.Rotary electrical machine according to claim 8, characterised in thatthe-base (17) of the fixing lug (16) has a width less than the width ofthe runner intended for receiving it and in that the fixing clamp device(22) comprises an element in the form of a wedge (28, 30, 32) whichengages in the gap (27) created when the base (17) is pushed in abutmentagainst the other support face (14) and provides by a wedging effect theimmobilisation of the base in its runner when the fixing screws (23) aretightened.
 10. Rotary electrical machine according to claim 9,characterised in that the clamp device (22) has the general shape of anL, one arm of which forms the aforementioned wedge element (28) whilstthe other arm comes into abutment on the protruding area (12) of theperiphery of the bearing.
 11. Rotary electrical machine according toclaim 10, characterised in that the clamp device (22) comprises a pieceforming a separate wedge (30) and a clamping plate (31) coming intoabutment on the protruding area (12) and the piece forming a wedge (30).12. Rotary electrical machine according to claim 10, characterised inthat the clamp device (22) comprises a piece forming a wedge (32) oftrapezoidal shape and a clamping plate (35) coming into abutment on thebase (17) of the lug (16) and the protruding area (12) and in that thewedging effect is produced by a clamping screw passing through the plateand the wedge piece (32) and during tightening drawing the wedge piece(32) towards the plate.
 13. Rotary electrical machine according to claim10, characterised in that the clamp device (22) comprises a clampingplate (39), part of which (40) comes into abutment on the protrudingarea (12) whilst another part (41) comes into abutment on an inclinedsurface forming a ramp (38) configured so as to produce a force pushingthe base (17) of the clamp (16) against the opposite runner support face(14) when the plate part (48) is clamped against the protruding area(12).
 14. Rotary electrical machine according to claim 2, characterisedin that a lug base (17) has, in the plane of its receiving runner, thegeneral shape of a U so as to leave free, in its central part, theventilation holes (9) formed in the peripheral wall of the bearing. 15.Rotary electrical machine according to claim 2, characterised in that alug base (17) comprises an aperture (42) for leaving free theventilation holes (9) formed in the peripheral wall of the bearing. 16.Rotary electrical machine according to claim 8, characterised in thatthe surface portions of the clamp device and of the fixing lug base (17)which are in abutment on each other are notched (24, 26), the notchesadvantageously extending perpendicularly to the axis of the machine inorder to improve the axial immobilisation of the fixing lugs (16). 17.Rotary electrical machine according to claim 5, characterised in thatthe face (20) for placing the base (17) of a fixing lug (16) on theperipheral surface of the bearing has a curvature corresponding to thatof the surface portion (21) of the bearing surface (5) between the twolateral support faces (14).